CVE-2026-21439

badkeys is a tool and library for checking cryptographic public keys for known vulnerabilities. In versions 0.0.15 and below, an attacker may inject content with ASCII control characters like vertical tabs, ANSI escape sequences, etc., that can create misleading output of the badkeys command-line tool. This impacts scanning DKIM keys (both --dkim and --dkim-dns), SSH keys (--ssh-lines mode), and filenames in various modes. This issue is fixed in version 0.0.16.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/badkeys/badkeys/commit/635a2f3b1b50a895d8b09ec8629efc06189f349a	Patch
https://github.com/badkeys/badkeys/commit/de631f69f040974bb5fb442cdab9a1d904c64087	Patch
https://github.com/badkeys/badkeys/issues/40	Exploit Issue Tracking Third Party Advisory
https://github.com/badkeys/badkeys/security/advisories/GHSA-wjpc-4f29-83h3	Third Party Advisory
https://github.com/badkeys/badkeys/issues/40	Exploit Issue Tracking Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:badkeys:badkeys:*:*:*:*:*:python:*:*

History

No history.

Information

Published : 2026-01-06 00:15

Updated : 2026-01-12 18:18

NVD link : CVE-2026-21439

Mitre link : CVE-2026-21439

CVE.ORG link : CVE-2026-21439

JSON object : View

Products Affected

badkeys

badkeys

CWE

CWE-150

Improper Neutralization of Escape, Meta, or Control Sequences

{"id": "CVE-2026-21439", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 2.0, "Automatable": "NOT_DEFINED", "attackVector": "LOCAL", "baseSeverity": "LOW", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "PROOF_OF_CONCEPT", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "LOW", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "published": "2026-01-06T00:15:49.027", "references": [{"url": "https://github.com/badkeys/badkeys/commit/635a2f3b1b50a895d8b09ec8629efc06189f349a", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/badkeys/badkeys/commit/de631f69f040974bb5fb442cdab9a1d904c64087", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/badkeys/badkeys/issues/40", "tags": ["Exploit", "Issue Tracking", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/badkeys/badkeys/security/advisories/GHSA-wjpc-4f29-83h3", "tags": ["Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/badkeys/badkeys/issues/40", "tags": ["Exploit", "Issue Tracking", "Third Party Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-150"}]}], "descriptions": [{"lang": "en", "value": "badkeys is a tool and library for checking cryptographic public keys for known vulnerabilities. In versions 0.0.15 and below, an attacker may inject content with ASCII control characters like vertical tabs, ANSI escape sequences, etc., that can create misleading output of the badkeys command-line tool. This impacts scanning DKIM keys (both --dkim and --dkim-dns), SSH keys (--ssh-lines mode), and filenames in various modes. This issue is fixed in version 0.0.16."}], "lastModified": "2026-01-12T18:18:59.067", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:badkeys:badkeys:*:*:*:*:*:python:*:*", "vulnerable": true, "matchCriteriaId": "AA459E08-D598-4832-942C-FF493A471141", "versionEndExcluding": "0.0.16"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}